Port the GIP protocol and authentication layers from medusalix/xone
into the C++ stack:
- crypto: SHA-256/HMAC (CommonCrypto), RSA PKCS#1 (Security.framework),
and a self-contained P-256 ECDH validated against OpenSSL vectors
- auth: v1 (RSA) and v2 (ECDH) handshake state machine
- gip: header/varint/chunk handling and packet dispatch, with the kernel
device model replaced by transport + client_listener interfaces
Adds test_crypto, test_auth, and test_gip suites.
Co-Authored-By: deepseek (deepseek/deepseek-v4-pro-0813): ported crypto, auth, and GIP
portersky